import numpy as np
A = None
p = 30
n = 100
while True:
    A = np.random.random((p,n))
    if np.linalg.matrix_rank(A) == p:
        break
x0 = np.random.random((n))
b = A @ x0
np.savetxt("A.txt",A)
np.savetxt("b.txt",b)
np.savetxt("x0.txt",x0)
